Auditory ossicle prosthesis with variable coupling surfaces

ABSTRACT

An auditory ossicle prosthesis ( 10 ) which comprises, at one end, a plate-shaped first securing element ( 11 ) for bearing on the tympanic membrane or on the footplate of the stirrup, and, at its other end, a second securing element ( 12 ) for mechanical connection to the ossicular chain or to the inner ear, and also a connection element ( 13 ) that connects the two securing elements so as to conduct sound, wherein the first securing element has a radially inner coupling area ( 14 ) for coupling the first securing element to the connection element, and also a plurality of web elements ( 15, 15′, 15 ″) for radial connection of the coupling area to radially outer portions ( 16, 16 ′) of the first securing element, is characterized in that the coupling area and/or the web elements and/or the radially outer portions are of such a geometric configuration that they together form pieces of a jigsaw from which the first securing element can be assembled in its entirety, wherein the individual jigsaw pieces can be joined to one another or removed from one another, and wherein the first securing element is inherently mechanically stable in the state with the jigsaw pieces joined together. This means that the number of different prostheses to be kept ready during an operation can be reduced to a single standard prosthesis, without losing the possibility of optimal adaptation of the prosthesis to the specific case of use.

BACKGROUND OF THE INVENTION

The invention relates to an auditory ossicle prosthesis which replacesor spans at least one member or parts of one member of the ossicularchain, wherein the auditory ossicle prosthesis comprises, at one end, asubstantially plate-shaped first securing element for bearing on thetympanic membrane or on the footplate of the stirrup, and, at its otherend, a second securing element for mechanical connection to a member orparts of a member of the ossicular chain or to the inner ear, and also aconnection element that connects the two securing elements to each otherso as to conduct sound, and wherein the plate-shaped first securingelement has a radially inner coupling area for mechanically coupling thefirst securing element to the connection element and also a plurality ofweb elements for radial connection of the radially inner coupling areato radially outer portions of the first securing element.

A device of this kind is known from DE 10 2007 013 708 B3.

Auditory ossicle prostheses are used to transmit sound or a sound signalfrom the tympanic membrane to the inner ear when the ossicles of thehuman middle ear are entirely or partially absent or damaged. Theauditory ossicle prosthesis has two ends, and, depending on the specificcircumstances, one end of the auditory ossicle prosthesis is secured tothe tympanic membrane, for example by means of a headplate, and theother end of the auditory ossicle prosthesis is secured, for example, tothe stirrup of the human ossicular chain or plunged directly into theinner ear. With the known auditory ossicle prostheses, the soundconduction or signal transmission between the tympanic membrane and theinner ear is often made possible only to a limited extent, since theseprostheses are able only to an extremely limited extent to replace thenatural anatomical features of the ossicular chain.

After the prosthesis has been placed surgically in the middle ear andthe tympanic membrane has been closed again, the so-called incorporationphase starts. During this period, scars and tissue strands form andgenerate unpredictable forces, which can lead to the prosthesis shiftingfrom its local position. In the case of a stiff connection betweenheadplate and shaft, increased pressure peaks can occur between the edgeof the headplate and the tympanic membrane or the transplant betweentympanic membrane and headplate. These pressure peaks can be so high asto result in penetration or extrusion through the tympanic membrane. Forthis reason, it is very useful if, after the operation, the prosthesishas a certain degree of mobility and flexibility, such that theheadplate is able to automatically adapt itself to the position of thetympanic membrane after the operation.

Since the anatomical features of the ear, for example the position,shape and size of the stirrup, anvil, hammer and tympanic membrane, alsovary between individuals, it is very advantageous if auditory ossicleprostheses are not made rigid, but instead have a certain flexibility orvariability.

To achieve this flexibility or variability, various securing andcoupling devices for auditory ossicles are known that have elastic partsand/or hinges. Such a hinged connection between a securing element,mounted on the footplate of the stirrup, and the elongate shaft isdescribed in EP 1 181 907 B1 and is offered by the Applicant under thebrand name “Ball-Joint”.

Another complication that occurs occasionally is the result ofinsufficient air in the middle ear cavity and of associated acute orchronic inflammations, tumor formations, adhesions in the region of thetympanic membrane and stiffening of the latter. In cases of dysfunctionof the Eustachian tube, for example, an underpressure may develop in themiddle ear and cause eversion or so-called retraction of the tympanicmembrane, with resulting adhesion to the stirrup, for example. Tocounteract this and to be able to follow the postoperative movements ofthe tympanic membrane, the headplates in known auditory ossicleprostheses are designed to be able to tilt relative to the connectionelement that connects the headplate to the second securing element andthat is in most cases designed as an elongate shaft. A headplate of thiskind, which is inherently rigid but is able to tilt relative to theconnection element, is described inter alia in US 2004/0162614 A1, inthe article by M. W. Yung, Ph.D, F.R.C.S, D.L.O. and C. Brewis, F.R.C.S.entitled “A comparison of the user-friendliness of hydroxyapatite andtitanium ossicular prostheses” in the Journal of Laryngology & Otology,February 2002, volume 116, pages 97-102, or, for example, also in US2006/0271190 A1.

However, a disadvantage of these known auditory ossicle prostheses isthat, in the event of local medial movements of the tympanic membrane,the inherently rigid tilting of the headplate means that the oppositeside of the headplate is also moved out laterally at the same time, as aresult of which pressure peaks are generated on the tympanic membrane.

In order to achieve a high level of postoperative flexibility andvariability of the prosthesis, while at the same time considerablyimproving the quality of the sound conduction through the prosthesis,without causing the above-mentioned complications to occur, theaforementioned document DE 10 2007 013 708 B3 proposes that the webelements are of such a geometric configuration that, in the event oflocal medial movement of the tympanic membrane, they are able to followthis medial movement locally, but do not transmit the movement to remoteareas of the headplate. In the event of a slight medial movement of thetympanic membrane, this flexible configuration of the auditory ossicleprosthesis avoids rigid tilting of the whole headplate. Instead, theheadplate twists upon itself locally but, in the event of movements ofthe tympanic membrane caused by sound, it nevertheless transmits thesemovements to the connection element, such that an optimal transmissionof the sound or of the sound signal from the tympanic membrane to themiddle ear and onward to the inner ear is ensured.

This provides a very considerable improvement over the rest of the knownprior art. Unfortunately, however, further problems still persist thatcannot be solved by these measures alone:

In the context of a tympanoplasty procedure in the human middle ear, thepathology and anatomy may necessitate very different kinds of structuralreconstructions that are specific to each individual patient. Dependingon the extent and shape of any parts of the middle ear anatomy that arestill present and that are perhaps partially intact, for example thehammer (malleus), the anvil (incus), the stirrup (stapes) or thetympanic membrane, the middle ear prostheses to be implanted need tohave a correspondingly large number of different geometries, some ofthem differing quite considerably in shape and size.

Since, before the start of surgery of the middle ear, it cannot bepredicted, or can be predicted only with great difficulty (only roughlyif at all, and practically never exactly), how the subsequentreconstruction of the tympanic membrane and of the ossicular chain willturn out in the course of the operation, a very large number of middleear prostheses with different geometries, shapes and sizes have to bekept ready for each operation that is to be performed, so as to ensurethat the surgeon can at all times select the most suitable prosthesisduring the operation, that is to say the prosthesis allowing him to dealwith the specific case in question. Otherwise, it may not be possible toguarantee optimal treatment.

Another factor is that said problems of adapting the auditory ossicleprosthesis during surgery may occur not only in the area where the firstsecuring element bears on the tympanic membrane, but also in the area ofa likewise plate-shaped second securing element which may be required toallow the prosthesis to bear on the footplate of the stirrup.Particularly for the area of a total reconstruction toward the innerear, a total prosthesis for this purpose normally has a stamp with astandard diameter of 0.8 mm. Surgeons often express the wish thatdifferent surface areas could be made available, depending on theintraoperative situation, to be placed onto the footplate of thestirrup. This desire among specialists would be satisfied by provisionof an additional securing element which is connected or can be connectedto the stamp and which, in terms of the size of its surface, would beable to be varied within wide limits.

If the auditory ossicle prosthesis is not a total prosthesis, and thefirst securing element is therefore not designed as a headplate forbearing on the tympanic membrane, but instead as a clip for securing theprosthesis on a member of the ossicular chain, the described problems ofadaptation occur exclusively at the inner ear end of the auditoryossicle prosthesis.

A further problem is that, throughout the world, extremely differentsurgical techniques are employed, which postulate different types ofreconstructions in the middle ear. These require suitably adapted middleear prostheses which differ greatly from one another in size and shapeand which again have to be kept ready during each operation in order toallow the surgeon to employ what he considers to be the best method ineach particular case.

SUMMARY OF THE INVENTION

In light of this, the object of the present invention is to improve amiddle ear prosthesis of the type described above by the simplestpossible technical means and at minimal cost, such that the number ofdifferent prostheses to be kept ready during an operation can beconsiderably reduced, preferably to a single standard prosthesis,without in so doing losing the possibility of optimal adaptation of theprosthesis in each particular case.

According to the invention, this object is achieved in a surprisinglysimple and effective way, by virtue of the fact that the coupling areaand/or the web elements and/or the radially outer portions are of suchgeometric configuration that they together form pieces of a jigsaw fromwhich the plate-shaped first securing element can be assembled in itsentirety, wherein the individual jigsaw pieces can be joined to oneanother or removed from one another, and wherein the first securingelement is inherently mechanically stable in the state with the jigsawpieces joined together.

The plate-shaped first securing element of the middle ear prosthesisaccording to the invention can be designed, for example, as a headplateplaced against the tympanic membrane in the context of a tympanoplastyprocedure and is constructed such that it is variable within very widelimits in terms of its shape and surface. During surgery, the prosthesisaccording to the invention, kept ready as a standard prosthesis, canthus be reconfigured very easily, very flexibly and in an extremelytargeted manner that meets the situation particular to a specificpatient.

Simple ad hoc changes can be made to the standard prosthesis accordingto the invention, for example to the angles, lengths or surface areas,to serve the purpose of greatly improved adaptation to each particularcase. Thus, the middle ear prosthesis according to the invention affordsthe operating surgeon an extremely high degree of variation andflexibility, without the previous requirement to keep in stock a largenumber of very different prosthesis shapes, sizes and geometries. It isthus possible for the surgeon, during the operation, to make specificchanges to the prosthesis that allow him to adapt or adjust theprosthesis specifically to the particular set of circumstances.

By means of the jigsaw technique used according to the invention, it isquite simple to change, for example, the size of the headplate of theprosthesis such that it touches only very specific areas of the tympanicmembrane, generally those that are known to play an essential role inacoustic transmission.

It often happens that the manubrium is present on the tympanic membrane,or indeed that it is missing, depending on how many previous operationshave been performed, which operating method was employed and whichspecific measure was taken. Accordingly, a headplate configuredaccording to the invention with a variable surface allows the operatingsurgeon to react precisely and correctly, i.e. allows the arearesponsible for the manubrium to be detached or, if need be, joined.

A similar situation also applies to the coupling of the auditory ossicleprosthesis to the footplate of the stirrup, where the inventivesurface-variable design of the corresponding plate-shaped securingelement is likewise able to offer a hitherto unknown intraoperativeflexibility in terms of optimal adaptation to the situation presented bythe individual patient.

The radially inner coupling area can be arranged centrally around thearea centroid of the plate-shaped first securing element.

The basic concept according to the invention can be doubly exploited ifboth securing elements are plate-shaped and constructed from jigsawpieces, wherein the first securing element serves as a flat headplatefor mechanical connection to the tympanic membrane, and the secondsecuring element is designed to allow the auditory ossicle prosthesis tobear on the footplate of the stirrup.

Another advantageous embodiment of the auditory ossicle prosthesisaccording to the invention is characterized in that at least oneradially innermost jigsaw piece is provided which contains the couplingarea, and in that at least one radially outer jigsaw piece forms a ringsurrounding the radially innermost jigsaw piece in the state when theyare joined together. Generally, several radial sequences of jigsaw ringswill be provided. In this way, as when peeling an onion, the surface ofthe first securing element can be reduced to a desired size depending onthe actual circumstances by removing a corresponding number of radiallyouter jigsaw rings. Moreover, by attaching the outer jigsaw ring lastremoved, a securing element that has been made too small can also beenlarged again, which further increases the degree of flexibilityavailable to the operating surgeon.

Embodiments of the invention are also preferred in which at least onejigsaw piece is provided which can be joined from the side onto at leastone other jigsaw piece at the outer edge of the plate-shaped firstsecuring element. This opens up a huge number of design possibilities interms of the geometric shape of the securing element. In particular, itis now no longer essential to implant symmetrical shapes, as wererequired hitherto with the available standard prostheses. Instead, theoperating surgeon is easily able, during the operation, to produce byhand an optimally adapted auditory ossicle prosthesis that istailor-made to the situation.

In advantageous developments of this class of embodiments, the jigsawpiece that can be joined on from the side is shaped as an appendix forthe hammer or the manubrium of the auditory ossicle prosthesis and, inthe state when joined together, protrudes radially outward from the edgeof the plate-shaped first securing element.

These developments can be further improved by the fact that the jigsawpiece that can be joined on from the side is anchored resiliently in thefirst securing element, which in particular makes inadvertentbreaking-off of the very fine miniature part upon joining to thesecuring element very difficult.

The resilient anchoring of the jigsaw piece can be achieved by means ofa simple clip element, for example.

In other advantageous variants, the jigsaw piece that can be joined onfrom the side is anchored in the first securing element with a snap-fitaction and thus secure against loss.

One class of embodiments of the invention is characterized in that, inthe state with the jigsaw pieces joined together, the plate-shaped firstsecuring element has apertures that extend through the plane of theplate. In this way it is also easy to achieve the above-mentionedasymmetrical configurations of the geometry of the securing element.Moreover, because of the apertures, the plate-shaped securing elementhas a high degree of flexibility with respect to local movements ofparts of the securing element out from the plane of the plate, which isparticularly advantageous especially in embodiments of the securingelement as a headplate for bearing on the tympanic membrane.

In an alternative class of embodiments, the plate-shaped first securingelement, in the state with the jigsaw pieces joined together, forms aninherently closed surface and has no apertures extending through theplane of the plate. By virtue of the design, the securing element isparticularly stiff against torsion.

An embodiment of the auditory ossicle prosthesis is very particularlypreferred in which the radially outer portions of the plate-shaped firstsecuring element form an outer ring area. This embodiment is suitable inparticular for the above-mentioned rapid and successive “onion peeling”reduction of the surface of the first securing element radially from theoutside inward.

One group of developments of this embodiment is characterized in thatthe radially outer ring area is uninterrupted and closed. In this way,by removing whole ring areas, the surface of the securing element can bemade symmetrically smaller, radially from the outside inward. Moreover,in the case of postoperative retractions, it is in this way possible toavoid the formation of dangerous points directed at the tympanicmembrane.

As an alternative to this, in another group of developments, theradially outer ring area has at least one interruption, preferablyseveral interruptions. In this way, in particular, asymmetrical shapescan be easily produced.

In developments of the embodiment described above, the radially outerring area can have an oval or circular shape, which is known per se fromthe prior art and will generally constitute the standard version of theauditory ossicle prosthesis according to the invention.

To make the auditory ossicle prosthesis easier to implant surgically, ina special variant the radially outer ring area can have a unilateralrecess for receiving the manubrium.

In another variant, the radially outer ring area of the plate-shapedfirst securing element has a bulge that extends radially outward in theplane of the plate and that is able to engage in structures of theossicular chain.

However, a variant is also possible in which the radially outer ringarea has an undulating outer contour, which proves favorable in specificgeometric situations in the middle ear, of the kind that may often befound in practice in the patient.

Another embodiment of the auditory ossicle prosthesis according to theinvention is characterized in that the web elements between the radiallyinner coupling area and the radially outer portions of the plate-shapedfirst securing element are uninterrupted, so as to increase the desiredflexibility mentioned above.

Alternatively, however, at least some web elements can also have aninterruption between the radially inner coupling area and the radiallyouter portions of the plate-shaped first securing element, whichincreases the flexibility in terms of the securing element twisting inthe plane of its plate.

Embodiments of the invention are particularly preferred in which the webelements of the plate-shaped first securing element are not rectilinearin the plane of the plate but instead extend in several curves, thusfurther strengthening the desired effect of local flexibility of atympanic membrane headplate and of only locally limited deflection inthe event of slight medial movements of the tympanic membrane. Moreover,in this way a headplate can more easily follow any postoperative changeof the tympanic membrane.

In other advantageous embodiments of the auditory ossicle prosthesisaccording to the invention, each web element is connected to at leasttwo other web elements, resulting in a kind of flexible network of webelements.

It is particularly expedient if the web elements have a maximum width band the radially outer ring area has a maximum width B, where 2b<B.

In order to achieve the desired flexibility in the case of a maximumwidth b of the web elements and a minimum diameter D of the plate-shapedfirst securing element, including the ring area, the following shouldapply: b≦0.05 D, preferably b≈0.03 D. In the prior art, for example inthe auditory ossicle prostheses described in US 2004/0162614 A1, theratio b/D is at least 0.1 or above.

It is also expedient if the plate-shaped first securing element of theauditory ossicle prosthesis according to the invention has a thickness,in particular a plate thickness t of between 0.01 mm and 0.5 mm,preferably of between 0.1 mm and 0.25 mm, and a minimum diameter D ofbetween 1.5 mm and 8 mm, preferably of between 2 m and 5 mm, and the webelements have a maximum width b of between 0.01 mm and 0.3 mm,preferably of between 0.05 mm and 0.2 mm.

In the auditory ossicle prosthesis according to the invention, theconnection element between the securing elements is generally designedas an elongate shaft, as is well known per se from the prior art.

In order to increase the above-mentioned flexibility and variation ofthe prosthesis, as is described per se in EP 1 181 907 B1, it ispossible, in a particularly preferred development of this embodiment, toprovide at least one ball joint on or in the elongate shaft. Variants inwhich the elongate shaft comprises a large number of further rotationelements adjoining one another, preferably as a ball joint chain, areadvantageous in terms of a high degree of postoperative mobility of theprosthesis.

Alternatively, however, in particularly simple and inexpensiveembodiments of the prosthesis according to the invention, the shaft canalso be made in one piece and be particularly rigid.

Depending on the individual defect that is to be remedied in a patientby use of the auditory ossicle prosthesis according to the invention, orthat is at least to be alleviated in terms of its effects, theconstruction of the prosthesis is designed accordingly. In manyembodiments of the invention used in practice, the first securingelement will comprise a headplate designed to bear on the tympanicmembrane. In many other embodiments, for example, the prosthesis can besecured at one end to the process of the anvil and at the other to thestirrup, or it can be plunged directly into the inner ear. In thisconnection, an advantageous design is one in which the auditory ossicleprosthesis is located at the end point of the hammer (umbo) or directlynext to it, as a result of which the maximum lever action is achievedfor mechanically transmitting sound through movements in the artificialor natural ossicular chain.

One class of embodiments of the auditory ossicle prosthesis according tothe invention is distinguished by the fact that the second securingelement is formed as a plate, as a sleeve, as a loop, as a closed bell,as a singly or multiply slit bell or as a clip for mechanical connectionto a further member of the ossicular chain.

In developments of these embodiments, the prosthesis is secured on theone hand to the tympanic membrane by way of the first securing elementdesigned as headplate and on the other hand to the anvil or to thestirrup by way of the second securing element.

In alternative embodiments, provision may be made that the auditoryossicle prosthesis is at one end coupled directly to the inner ear, inparticular via a plunger, by means of perforation of the footplate ofthe stirrup (stapedectomy or stapedotomy) and/or by means of opening thehuman cochlea (cochleotomy).

Embodiments of the invention are possible in which the prosthesis orparts thereof is/are made of biocompatible plastics, in particularsilicone, polytetrafluoroethylene (PTFE) or polyether ether ketone(PEEK) and/or composite fiber materials, in particular carbon fibers.Post-operative rejection reactions can in most cases be avoided usingthese materials.

The auditory ossicle prosthesis according to the invention or partsthereof can be made of titanium and/or of gold and/or of tantalum and/orof steel and/or of an alloy of said metals. In addition to its strengthand excellent sound conduction properties, the material titanium inparticular also has excellent biocompatibility in the middle ear inhumans.

In view of the above-mentioned post-operative adjustment of position,embodiments of the invention are advantageous in which the prosthesis orparts thereof, in particular one of the securing elements, is made of amaterial with shape memory or with superelastic properties, preferablynitinol, which is known per se from, for example, WO 02/069850 A1 orU.S. Pat. No. 6,554,861 B2.

In further embodiments, parts of the auditory ossicle prosthesis canalternatively or additionally be made from a ceramic material.

In addition to the post-operative change of position, a further problemalso arises after implantation of auditory ossicle prostheses. This isdue to the fact that the middle ear of the human body constitutes a“semi-open bearing”. Any implantation material introduced into the body,in the context of a reconstruction of the middle ear and of itsstructures, is therefore subject to a particular stress arising from thefact that it lies in a contaminated and infected environment, whichgenerally attacks the material. Since the aim of implanting an auditoryossicle prosthesis must be that the implant remains in the patient'smiddle ear for as long as possible and without complications, aprotracted attack of the material can lead to damage of the prosthesisand/or to local infection. Both consequences are unacceptable. Toprevent damage of the implanted material and also of the surroundingtissue on a permanent basis, another particularly preferred embodimentof the invention involves a biologically active coating, in particular acoating that inhibits growth and/or promotes growth and/or has anantibacterial action, being provided at least in some areas of thesurface of the auditory ossicle prosthesis.

In the auditory ossicle prosthesis according to the invention, asecuring element designed as headplate should in principle have acoating that promotes growth, whereas a securing element leadingdirectly into the ear, and designed in the form of a plunger forexample, should have a coating that inhibits growth.

An embodiment of the auditory ossicle prosthesis according to theinvention is particularly preferred in which the weight distribution ofthe individual parts of the prosthesis is calculated as a function of adesired, predefinable frequency response of the sound conduction in themiddle ear. It is thus possible, without major additional technicaloutlay, to achieve a degree of mechanical tuning of the soundpropagation properties by means of an individually configured auditoryossicle prosthesis.

Such a tuning effect can be achieved, in particular embodiments, by thefact that at least one additional weight is secured on a part of theossicular chain or of the prosthesis as a function of a desired,predefinable frequency response of the sound conduction in the middleear. In advantageous developments of these embodiments, the additionalweight is secured on a part of the ossicular chain or the prosthesis bymeans of a clip. In addition, the additional weight and/or the clip canalso be coated with a biologically active coating.

A further embodiment of the invention, finally, is distinguished by thefact that the prosthesis is connected to an active vibration part of anactive, in particular implantable hearing aid. In this way, extensivehearing damage can also be largely remedied by application of modernelectronics or can at least be substantially alleviated in terms of itseffects, in which case, on account of the above-described coating, aphysical connection of the prosthesis to the outside world does notcause any problems resulting from increased bacterial ingress into thearea of the middle ear, if the coating is made suitably antibacterial.

Further features and advantages of the invention will become clear fromthe following detailed description of illustrative embodiments of theinvention, from the figures in the drawing, which shows importantdetails of the invention, and also from the claims. The individualfeatures can each be realized singly or in any desired combinations invariants of the invention.

Illustrative embodiments of the invention are depicted in the schematicdrawing and are explained in more detail in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures of the drawing are divided into groups of three, therespective individual figures of a group being distinguished from oneanother by a number followed by a, b or c. The “a” figures in each caseshow a schematic perspective view of an embodiment of the auditoryossicle prosthesis according to the invention; the “b” figures show thefirst securing element from the “a” figure, and designed according tothe invention, in the assembled state of the jigsaw pieces; and the “c”figures show the first securing element from the corresponding “b”figure in the state when the jigsaw pieces are disassembled. Moreover,elements having the same structure and/or the same function areidentified by the same reference number in the drawing.

FIGS. 1 a-c show an embodiment of the auditory ossicle prosthesisaccording to the invention with a first securing element which isdesigned as a tympanic membrane headplate and has an annular structure,and with a second securing element designed as a slotted bell at theother end of the connection element;

FIGS. 2 a-c show an embodiment with two plate-shaped securing elements;

FIGS. 3 a-c show an embodiment with a jigsaw piece which is shaped as anappendix for the hammer or the manubrium and can be joined to the firstsecuring element from the side, and with a clip-shaped second securingelement;

FIGS. 4 a-c show an embodiment with a jigsaw piece that can be joined onfrom the side and with a radially outwardly extending bulge of the firstsecuring element, after the jigsaw piece that can be joined on has beenremoved;

FIGS. 5 a-c show an embodiment with a jigsaw piece that can be joined onfrom the side and that is anchored resiliently in the firstsecuring-element;

FIGS. 6 a-c show an embodiment with a jigsaw piece that can be joined onfrom the side and that is anchored in the first securing element bymeans of a clip element;

FIGS. 7 a-c show an embodiment with a jigsaw piece that can be joined onfrom the side and that is anchored with a snap-fit action in the firstsecuring element;

FIGS. 8 a-c show an embodiment in which the plate-shaped first securingelement, in the state with the jigsaw pieces joined together, forms aninherently closed surface and has no apertures extending through theplane of the plate; and

FIGS. 9 a-c show an embodiment with a first securing element which isdesigned as a tympanic membrane headplate and has an annular structure,with a ball joint in the connection element, and with a second securingelement shaped like a plunger.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The auditory ossicle prostheses 10; 20; 30; 40; 50; 60; 70; 80; 90according to the invention each have, at one end, a plate-shaped firstsecuring element 11; 21; 31; 41; 51; 61; 71; 81; 91 which is designed inthe form of a headplate for bearing on the tympanic membrane or as afootplate for bearing on the footplate of the stirrup. At the other endof the auditory ossicle prostheses 10; 20; 30; 40; 50; 60; 70; 80; 90,there is a second securing element 12; 22; 32; 92 for mechanicalconnection of the prosthesis to a member or parts of a member of theossicular chain or directly to the inner ear. Arranged between these isa connection element 13; 23; 93 which connects the two securing elementsto each other so as to conduct sound and which, in the embodimentsshown, is designed in the form of a one-part or multi-part, short orlong shaft.

The plate-shaped first securing element 11; 21; 31; 41; 51; 61; 71; 81;91 in each case has a radially inner coupling area 14; 24; 34; 44; 54;64; 74; 84; 94, arranged around its area centroid, for mechanicallycoupling the first securing element to the connection element 13; 23;93, and also a plurality of web elements 15, 15′, 15″; 25, 25′, 25″; 35,35′, 35″, 35′″; 45, 45′; 55, 55′, 55″; 65, 65′; 75, 75′, 75″; 85, 85′;95, 95′ for radial connection of the radially inner coupling area toradially outer portions 16, 16′; 26, 26′; 36, 36′; 46, 46′; 56, 56′; 66,66′; 76, 76′; 86, 86′; 96, 96′ of the first securing element 11; 21; 31;41; 51; 61; 71; 81; 91.

The coupling area 14; 24; 34; 44; 54; 64; 74; 84; 94 and/or the webelements 15, 15′, 15″; 25, 25′, 25″; 35, 35′, 35″, 35′″; 45, 45′; 55,55′, 55″; 65, 65′; 75, 75′, 75″; 85, 85′; 95, 95′ and/or the radiallyouter portions 16, 16′; 26, 26′; 36, 36′; 46, 46′; 56, 56′; 66, 66′; 76,76′; 86, 86′; 96, 96′ are of such a geometric configuration that theytogether form pieces of a jigsaw from which the plate-shaped firstsecuring element 11; 21; 31; 41; 51; 61; 71; 81; 91 can be assembled inits entirety, wherein the individual jigsaw pieces can be joined to oneanother or removed from one another, and wherein the first securingelement 11; 21; 31; 41; 51; 61; 71; 81; 91 is inherently mechanicallystable in the state with the jigsaw pieces joined together.

The embodiment shown in FIGS. 1 a-c has a headplate as first securingelement 11, a short, rigid one-piece shaft as connection element 13, anda second securing element 12 with a bell-shaped configuration which isused to secure the auditory ossicle prosthesis 10 to a member of theossicular chain, for example to the anvil or to the stirrup. The firstsecuring element 11 has apertures extending through the plane of theplate in order to increase the flexibility of the headplate whentwisting in and out of the plane of the plate, and it comprises aradially inner jigsaw piece 16 that contains the coupling area 14. Aradially outer jigsaw piece 16′ forms a ring surrounding the radiallyinner jigsaw piece 16 when they are joined together, the radially outerring area having a circular shape and an uninterrupted and closedprofile.

In the embodiment according to FIGS. 2 a-c , both securing elements 21,22 have a plate-shaped configuration and, according to the invention,are constructed from jigsaw pieces, wherein the first securing element21 is designed to allow the auditory ossicle prosthesis 20 to bear onthe footplate of the stirrup, while the second securing element 22serves as a flat headplate for mechanical connection to the tympanicmembrane. Since this constitutes a total prosthesis, the shaft-likeconnection element 23 is slightly longer than the short shaft 13 in FIG.1 a. In the first securing element 21 also, a radially inner jigsawpiece 26 containing the coupling area 24 is surrounded in a ring shapeby a radially outer jigsaw piece 26′, but both the radially inner ringarea and also the radially outer ring area each have an interruptionthat increases the flexibility of the plate-shaped first securingelement 21 when twisting in and out of the plane of the plate.

The embodiments in FIGS. 3 a to 9 c are distinguished by the fact thatat least one jigsaw piece 36′; 46′; 56′; 66′; 76′; 86′; 96′ is in eachcase provided that can be joined from the side onto at least one otherjigsaw piece 36; 46; 56; 66; 76; 86; 96 at the outer edge of theplate-shaped first securing element 31; 41; 51; 61; 71; 81; 91. In theembodiments in FIGS. 3 a to 7 c, this jigsaw piece 36′; 46′; 56′; 66′;76′ that can be joined on from the side is shaped in each case as anappendix for the hammer or the manubrium of the auditory ossicleprosthesis 30; 40; 50; 60; 70 and, in the assembled state, protrudesradially outward from the edge of the plate-shaped first securingelement 31; 41; 51; 61; 71.

The second securing elements 32; 72 in the auditory ossicle prostheses30; 70 according to FIGS. 3 a; 7 a are each designed as clips withseveral tongues, whereas in the embodiments according to FIGS. 4 a to 6a they each have a slotted bell shape like the second securing element12 in FIG. 1 a.

The plate-shaped first securing element 41 in the embodiment accordingto FIGS. 4 a-c is distinguished by the fact that its first jigsaw piece46 has, in the radially outer ring area, a bulge 47 which extendsradially outward in the plane of the plate and which, even without thesecond jigsaw piece 46′ joined on from the side, can serve as anappendix for the hammer or the manubrium of the auditory ossicleprosthesis 40.

In the first securing elements 51; 61; 71 of the auditory ossicleprostheses 50; 60; 70 according to FIGS. 5 a to 7 c, the jigsaw piece56′; 66′; 76′ that can be joined on from the side is in each caseanchored resiliently in the first securing element 51; 61; 71.

The jigsaw pieces 66′; 76′ that can be joined on in the embodimentsaccording to FIGS. 6 a to 7 c can each be laterally anchored in therespective first jigsaw piece 66; 76 of the first securing element 61;71 by means of a pair of web elements 65′; 75′ designed as a clipelement.

In the embodiment according to FIGS. 6 a-c, the radially outer ring areaof the first securing element 61 has a unilateral recess 67 forreceiving the manubrium when the jigsaw piece 66′ that can be joined onis not used.

In the auditory ossicle prosthesis 70 according to FIGS. 7 a-c, thejigsaw piece 76′ that can be joined on from the side is anchored with asnap-fit action, and thus secure against loss, in the first securingelement 71 by means of barbs 77 provided at the ends of the two webelements 75″.

FIGS. 8 a-c show an embodiment of the invention in which, in the statewith the jigsaw pieces 86, 86′ joined together, the plate-shaped firstsecuring element 81 forms an inherently closed surface and has noapertures extending through the plane of the plate, as a result of whichthe plate is relatively stiff against twisting.

FIGS. 9 a-c, finally, show an embodiment with a first securing element91 again designed as a headplate for bearing on the tympanic membrane.In the present illustrative embodiment, the second securing element 92at the end remote from the headplate in the auditory ossicle prosthesis90 shown in FIG. 9 a is designed as a plunger for direct coupling of theauditory ossicle prosthesis 90 to the inner ear. The shaft-shapedconnection element 93 is here constructed in two parts and, between itstwo parts, has a ball joint 97 in order to increase the mechanicalflexibility of the shaft.

The weight distribution of the individual parts of the auditory ossicleprosthesis 10; 20; 30; 40; 50; 60; 70; 80; 90 according to the inventioncan be calculated as a function of a desired, predefinable frequencyresponse of the sound conduction in the middle ear, in such a way thatindividual tuning of the sound conduction properties is made possible.

In other embodiments of the auditory ossicle prosthesis according to theinvention that are not specifically shown in the drawing, the centralcoupling areas and/or the web elements and/or the radial outer portionscan also have other geometries in order to achieve the desired surfacevariability of the respective first securing element. For example, atleast some of the web elements can have an interruption between thecentral coupling area and the radially outer portions. The radiallyouter portions can also be designed with one or more interruptions, canhave an undulating outer contour and/or a unilateral recess forreceiving the manubrium.

1. An auditory ossicle prosthesis which replaces or spans at least onemember or parts of one member of an ossicular chain, the auditoryossicle prosthesis comprising: at one end, a substantially plate-shapedfirst securing element for bearing on a tympanic membrane or on afootplate of a stirrup, and, at its other end, a second securing elementfor mechanical connection to a member or parts of a member of anossicular chain or to an inner ear, and also a connection elementconnecting the first and second securing elements to each other so as toconduct sound, and wherein the substantially plate-shaped first securingelement has a radially inner coupling area mechanically coupling thesubstantially plate-shaped first securing element to the connectionelement, and also a plurality of web elements radially connecting theradially inner coupling area to at least one radially outer portion ofthe substantially plate-shaped first securing element, wherein theradially inner coupling area and/or the web elements and/or the at leastone radially outer portion are of such a geometric configuration thatthey together form jigsaw pieces of a jigsaw puzzle from which thesubstantially plate-shaped first securing element can be assembled inits entirety with the pieces of the jigsaw puzzle being non-rotatablerelative to each other, wherein the jigsaw pieces can be joined to oneanother or removed from one another, and wherein the substantiallyplate-shaped first securing element is inherently mechanically stable ina state with the jigsaw pieces joined together.
 2. The auditory ossicleprosthesis according to claim 1, wherein both the first and the secondsecuring elements are plate-shaped and are constructed from the jigsawpieces, wherein the substantially plate-shaped first securing elementcomprises a flat headplate for mechanical connection to the tympanicmembrane, and the second securing element is designed to allow theauditory ossicle prosthesis to bear on the footplate of the stirrup. 3.The auditory ossicle prosthesis according to claim 1, wherein theradially inner coupling area comprises at least one radially innerjigsaw piece and the at least one radially outer portion comprises atleast one radially outer jigsaw piece, with the at least one radiallyouter jigsaw piece forming a ring that surrounds the radially innerjigsaw piece when the radially inner coupling area, the web elements andthe at least one radially outer portion are connected together.
 4. Theauditory ossicle prosthesis according to claim 1, wherein at least afirst one of the jigsaw pieces is provided that can be joined from aside thereof onto at least a second one of the jigsaw pieces at theouter edge of the substantially plate-shaped first securing element. 5.The auditory ossicle prosthesis according to claim 4, wherein the firstone of the jigsaw pieces that can be joined from the side thereof isshaped as an appendix for a hammer or a manubrium of the auditoryossicle prosthesis and, when the radially inner coupling area, the webelements and the at least one radially outer portion are connectedtogether, protrudes radially outward from the outer edge of thesubstantially plate-shaped first securing element.
 6. The auditoryossicle prosthesis according to claim 4, wherein the first one of thejigsaw pieces that can be joined from the side is anchored resilientlyin the substantially plate-shaped first securing element.
 7. Theauditory ossicle prosthesis according to claim 6, wherein the first oneof the jigsaw pieces that can be joined from the side is anchored in thesubstantially plate-shaped first securing element by a clip element. 8.The auditory ossicle prosthesis according to claim 4, wherein the firstone of the jigsaw pieces that can be joined from the side is anchoredwith a snap-fit action in the substantially plate-shaped first securingelement.
 9. The auditory ossicle prosthesis according to claim 1,wherein, when the radially inner coupling area, the web elements and theat least one radially outer portion are connected together, thesubstantially plate-shaped first securing element has aperturesextending through a plane in which the substantially plate-shaped firstsecuring element is disposed.
 10. The auditory ossicle prosthesisaccording to claim 1, wherein, when the radially inner coupling area,the web elements and the at least one radially outer portion areconnected together, the substantially plate-shaped first securingelement forms an inherently closed surface and has no aperturesextending through a plane in which the substantially plate-shaped firstsecuring element is disposed.
 11. The auditory ossicle prosthesisaccording to claim 1, wherein the at least one radially outer portion ofthe substantially plate-shaped first securing element forms an outerring area.
 12. The auditory ossicle prosthesis according to claim 11,wherein the outer ring area of the substantially plate-shaped firstsecuring element is uninterrupted and closed.
 13. The auditory ossicleprosthesis according to claim 11, wherein the outer ring area of thesubstantially plate-shaped first securing element has at least oneinterruption.
 14. The auditory ossicle prosthesis according to claim 11,wherein the outer ring area of the substantially plate-shaped firstsecuring element has an oval or circular shape.
 15. The auditory ossicleprosthesis according to claim 11, wherein the outer ring area of thesubstantially plate-shaped first securing element has a bulge extendingradially outwardly in a plane in which the substantially plate-shapedfirst securing element is disposed.
 16. The auditory ossicle prosthesisaccording to claim 11, wherein the outer ring area of the substantiallyplate-shaped first securing element has a unilateral recess forreceiving a manubrium.
 17. The auditory ossicle prosthesis according toclaim 11, wherein the outer ring area has an undulating outer contour.18. The auditory ossicle prosthesis according to claim 1, wherein theweb elements between the radially inner coupling area and the at leastone radially outer portion of the substantially plate-shaped firstsecuring element are uninterrupted.
 19. The auditory ossicle prosthesisaccording to claim 1, wherein at least one of the web elements has aninterruption between the radially inner coupling area and the at leastone radially outer portion of the substantially plate-shaped firstsecuring element.
 20. The auditory ossicle prosthesis according to claim1, wherein the web elements of the substantially plate-shaped firstsecuring element are not rectilinear in a plane in which thesubstantially plate-shaped first securing element is disposed, butinstead extend along curved paths within the plane.
 21. The auditoryossicle prosthesis according to claim 1, wherein each web element isconnected to at least two other web elements.
 22. The auditory ossicleprosthesis according to claim 1, wherein the radially inner couplingarea is arranged centrally around an area centroid of the substantiallyplate-shaped first securing element.
 23. The auditory ossicle prosthesisof claim 1, wherein one of the jigsaw puzzle pieces includes a bulbousprojection configured to be received within a correspondingly shapedbulbous receptacle of the other of the jigsaw puzzle pieces.
 24. Anauditory ossicle prosthesis which replaces or spans at least one memberor parts of one member of an ossicular chain, said auditory ossicleprosthesis comprising: a substantially plate-shaped first securingelement defining one end of said auditory ossicle prosthesis for bearingon a tympanic membrane or on a footplate of a stirrup, said firstsecuring element comprising a radially inner coupling area, a radiallyouter portion and a plurality of web elements radially connecting saidinner coupling area to said outer portion; a second securing elementdefining an opposite end of said auditory ossicle prosthesis formechanical connection to a member or parts of a member of an ossicularchain or to an inner ear; and a connection element interconnecting saidfirst and second securing elements to one another so as to conductsound, said connection element being mechanically coupled to said firstsecuring element by said inner coupling area; wherein at least two of:said inner coupling area; one of said web elements; and said outerportion of said first securing element define respective independent anddiscrete first and second jigsaw puzzle pieces from which said firstsecuring element can be assembled in its entirety, said first and secondjigsaw puzzle pieces defining respective complementary geometricportions disposed in interlocking but releasable engagement with oneanother, an overall shape of said first securing element being variablebefore or during implantation of said auditory ossicle prosthesis withinan ossicular chain by disengaging said first jigsaw puzzle piece fromsaid second jigsaw puzzle piece or by engaging said first jigsaw puzzlepiece with said second jigsaw puzzle piece.
 25. The auditory ossicleprosthesis of claim 24, wherein said geometric portion of said firstjigsaw puzzle piece defines a bulbous projection and said geometricportion of said second jigsaw puzzle piece defines a bulbous receptaclewhich receives said bulbous projection to interlock said first andsecond jigsaw puzzle pieces with one another.
 26. The auditory ossicleprosthesis of claim 24, wherein top surfaces of the first and secondjigsaw puzzle pieces are co-planar and together form a top plane of thefirst securing element and bottom surfaces of the first and secondjigsaw puzzle pieces are opposite the top surfaces of the first andsecond jigsaw puzzle pieces, the bottom surfaces being co-planar andtogether forming a bottom plane of the first securing element, and thefirst and second jigsaw puzzle pieces interlock with one anotherentirely within an area located between the top plane and the bottomplane of the first securing element.
 27. The auditory ossicle prosthesisof claim 26, wherein said geometric portion of said first jigsaw puzzlepiece defines a projection and said geometric portion of said secondjigsaw puzzle piece defines a receptacle which receives said projectionto interlock said first and second jigsaw puzzle pieces with oneanother.
 28. The auditory ossicle prosthesis of claim 24, wherein saidfirst and second jigsaw puzzle pieces are non-rotatable relative to oneanother when interlocked with one another.
 29. The auditory ossicleprosthesis of claim 24, wherein an outer circumferential surface of thefirst jigsaw puzzle piece is non-circular.
 30. The auditory ossicleprosthesis of claim 24, wherein the first jigsaw puzzle piece and thesecond jigsaw puzzle piece engage along a first direction of movement,and the first jigsaw puzzle piece and the second jigsaw puzzle piece areprevented from moving relative to each other only in a second directionperpendicular to the first direction when the first jigsaw puzzle pieceand the second jigsaw puzzle piece are engaged.